Those shocked by a 100k+ salary (again, factor in all those fees and payouts), do not make their living in this industry, clearly - and certainly not in NYC.
Also, remember Broadway is the top of the stage heap. This is the furthest you can go in a stage career in the US. So, to compare it to another profession, you'd have to compare it to *the* most successful people of that profession. And then, I bet the successful people in that profession make comparable or more.
Also, it's worth noting the original cast of this play may not be well-known and the audiences are coming for the play and not the cast, but they originated these parts and likely had a strong influence of the development and success of the play. So, as it rakes in 2+ million/wk, they're right to ask for a larger cut.
If they have offers in TV and film, good for them, though - that's likely better pay.